From AUD $55.00
  • Duration: 2 Hours (approx.)
  • Location: Julimar, WA
  • Product code: BMoonS
lWhat Is a Blue Moon?

The phrase, once in a Blue Moon, is colloquially used to suggest that something is very rare. But just how rare, depends on your definition.

In astronomy, a Blue Moon is defined as either the 3rd Full Moon of an astronomical season with 4 Full Moons or as the 2nd Full Moon in a calendar month.- Special Event 

How Rare Are Blue Moons?

Blue Moon is a term that is used to describe the 3rd Full Moon of an astronomical season that has 4 Full Moons.

There are 4 astronomical seasons in a year:

When 1 of the seasons in a year has 4 Full Moons, instead of the usual 3, the 3rd Full Moon is called a Blue Moon.

These days, the 2nd Full Moon in a calendar month is also often referred to as a Blue Moon. This particular use was popularized due to a miscalculation published in a 1946 article in Sky and Telescopemagazine. Such Blue Moons occur rather frequently - at least once every 2 or 3 years.

Not Really Blue

A Blue Moon is not actually blue in color. However, blue colored Moons do rarely occur when dust or smoke particles in the air are of a specific size. Such particles help create a blue colored Moon by scattering blue light.

Moons which appear red can be caused by other sizes of dust particles or by a total lunar eclipse. These are much more common than Blue Moons.

Did You Know?

About once every 19 years, the month of February does not have a Full Moon, which is known as a Black Moon. The years when this happens also have 2 Full Moons in 2 different months.